The present invention relates to a power plant for electric earth-moving and agricultural vehicles with four-wheel drive.
Vehicles with a hydraulic drive controlled by a pump which is driven by an internal-combustion engine are also known for earth-moving and agricultural work: in particular, some vehicles can be fitted, at the front or at the rear, with buckets, loading shovels, blades, lifting forks, excavators, mills, drills, rotating brushes or equipment of any kind which is actuated hydraulically. Power plants for vehicles of this type are extremely effective, but when used in enclosed spaces, such as mines, basements, ship holds, industrial buildings, historical city centers, cemeteries or the like, they have the drawback that their internal-combustion engines emit exhaust gases and produce noise at levels which are particularly unwanted in such environments.
In practice, there is the need for vehicles which reduce the coefficients of acoustic and chemical aggressiveness and which in giving broad assurances of environment-friendliness have a gentle impact on the user and on the citizens involved.
On the other hand, differently from battery-powered electric-drive vehicles known as fork-lift trucks, which are meant to usually work on level ground and on the same site, earth-moving vehicles must be able to travel for significant stretches on roads, including unpaved roads, without stations for recharging or replacing the batteries.
The aim of the present invention is to provide a power plant for electric earth-moving and agricultural vehicles with four-wheel drive which can travel over significant distances on roads, can operate without emitting toxic gases, can be fitted with equipment of any kind which can be actuated hydraulically and has a significant operating range.
Within the scope of this aim, an object of the present invention is to provide a structure which is simple, relatively easy to provide in practice, safe in use, effective in operation and relatively modest in cost.
This aim, this object and others which will become apparent hereinafter are achieved by a power plant for electric earth-moving and agricultural vehicles with four-wheel drive according to the present invention, characterized in that it comprises a supporting chassis, an electric motor drive for the driving wheels of the vehicle which comprises a gear-type reduction and distribution unit which is installed in a housing which is rigidly coupled to said chassis, at least two electric motors whose body is fixed to said housing, a front longitudinal distribution shaft and a rear longitudinal distribution shaft which protrude from said housing, two differentials which are fitted at the ends of said distribution shafts and from which a front axle and a rear axle respectively protrude for respective pairs of driving wheels, at least one of said axles being provided with steering elements, and an assembly for the oscillating support of said front axle which is fixed, in a downward region, to the front end of said supporting chassis.